Refrigeration oil and other materials used with refrigerant for refrigerators or air conditioners should have thermal and chemical stability to maintain the system reliability. Some kinds of synthetic oil are used for alternative refrigerant, HFC’s and hydrolysis, material compatibility, and low-temperature extraction of contaminant or sludge are important subjects. Much more numbers and times ...

More than one year has passed since refrigerant for refrigerator was changed from CFC12 to HFC134a. Long term reliability of refrigerator in HFC134a refrigerant system is mainly dependent on lubrication of moving parts of compressor and clogging of capillary tube. To maintain better practical reliability in components in compressor such as refrigeration lubricant,metallic materials and motor in...

Fin-tube heat exchangers are widely used in air-conditioners and heat pumps, which are constructed with a lot of tubes. Refrigerant circuit of heat exchanger with numerous pipe can be constructed by many methods. Refrigerant circuit design is usually determined designer’s experience and case by case test without guides. The number of path affects largely on heat exchanger performance. In this p...

• Improved alignment of magnetic field and fluid flow raises efficiency. Experiments prove the insensitivity device performance to profile. Overall, results show efficiency can be conserved while halving magnet volume, cost. Magnetocaloric heat pumping near room temperature, a.k.a. cooling, relies on active regenerator cycle achieve functional temperature spans realize economic societal benefit...

CFD was applied to evaluate the performance of both existing and improved designs for refrigerant distributors. In general, it is better to utilize a spherical base as compared with other shapes and to locate the orifice close to distributor base. These changes tend to improve the robustness of the distributor in terms of providing even flow and phase distribution in different outlet branches w...

Due to the undesirable environmental consequences ofR12, there is a great challenge to find a suitable substitute for Rl2. A new refrigerant blend Rl34a!R218/R600a (88'Yoi9'Yol 3%) called JSCEON 49 has been developed as a long term, zero ozone depletion-potential replacement for Rl2. A computer program was written to calculate the cycle characteristics, such as cooling capacity, coefficient of ...

refrigerants that are used in refrigeration systems, cause environmental difficulties such as depletion of ozone layer and greenhouse effect. thus, we must find substitutes for such refrigerants, in this paper, the effect of refrigerant on the thermodynamics performance of refrigeration cycles are studied. to do this, a refrigerator that has designed for r12, is simulated. results show that pur...

Potential improvements of the Coefficient of Performance (COP) were investigated for R-407C at cooling and heating conditions of a residential heat pump. The study used CYCLE-11, a semi-theoretical vapor-compression cycle model, which was upgraded to simulate cross-flow, counter-flow, and parallel-flow evaporator and condenser with no restrictions on specifying superheated vapor and subcooled l...